/**
 * Created by 李威 on 2021/9/13.
 */

/*
* document:HTML文档
* querySelector
*
* */
var element1 = document.querySelector("button");
console.log(element1);
var element2 = document.querySelector(".username");
console.log(element2);
var element3 = document.querySelector("input[type = password]");
console.log(element3);